Specific inhalation challenge in the diagnosis of occupational asthma: consensus statement

Abstract

This consensus statement provides practical recommendations for specific inhalation challenge (SIC) in the diagnosis of occupational asthma. They are derived from a systematic literature search, a census of active European centres, a Delphi conference and expert consensus. This article details each step of a SIC, including safety requirements, techniques for delivering agents, and methods for assessing and interpreting bronchial responses. The limitations of the procedure are also discussed.Testing should only be carried out in hospitals where physicians and healthcare professionals have appropriate expertise. Tests should always include a control challenge, a gradual increase of exposure to the suspected agent, and close monitoring of the patient during the challenge and for at least 6 h afterwards. In expert centres, excessive reactions provoked by SIC are rare.A positive response is defined by a fall in forced expiratory volume in 1 s o15% from baseline. Equivocal reactions can sometimes be clarified by finding changes in nonspecific bronchial responsiveness, sputum eosinophils or exhaled nitric oxide. The sensitivity and specificity of SIC are high but not easily quantified, as the method is usually used as the reference standard for the diagnosis of occupational asthma. @ERSpublications ERS Task Force: a statement on specific inhalation challenges in the diagnosis of occupational asthma

EAACI position paper: irritant‐induced asthma

“…In patients who report ongoing worsening of their asthma symptoms at work, an adverse role of the workplace can be documented by assessing symptoms, pulmonary function and medication use during working periods and a vacation or temporary removal from work. In these patients, specific inhalation challenges in the laboratory or workplace challenges may be used as an attempt to distinguish IIA from work-exacerbated asthma and sensitizer-induced OA, although challenge tests with irritant substances are still poorly standardized (61).…”

En baker med astma

“…Spesifikk bronkial provokasjon (specific inhalation challenge, SIC) anses som referansemetode ved årsaksdiagnostikk av allergisk yrkesastma (2,6). Metoden har tidligere vaert i omfattende bruk i Norge innen allergologisk praksis, men har gått ut av bruk i dette fagfeltet (12).…”

“…Ettersom det ikke var blitt utført objektiv astmadiagnostikk mens pasienten var i eksponering, og det ikke lenger var mulig å få gjennomført en registrering av toppstrømshastighet (PEF) i arbeid og fritid (2), ble det funnet indikasjon for å utføre en spesifikk bronkial provokasjon mot melstøv for naermere diagnostikk. Provokasjonen ble utført etter anbefalinger publisert av en arbeidsgruppe nedsatt av European Respiratory Society (ERS), som har vurdert metoden med tanke på risiko, prosedyre og tolkning (6 Det ble konkludert med at pasienten hadde en klart signifikant positiv provokasjonstest etter eksponering for rugmelstøv med sikker straksreaksjon og mulig senreaksjon, altså en antydet bifasisk reaksjon (fig 1).…”

Specific inhalation challenge tests for occupational asthma in Europe: a survey

“…Nonetheless, we suggest that access to occupational SIC testing in Europe should be broader and provided at least on a national level in each country. We hope that these findings and those in the full Task Force report [6] will provide the necessary impetus for this development. …”

“…There is more variation in procedure, especially in the practice of admitting patients to hospital, in the use of devices that deliver precise doses of challenge agent and in the measurement of (secondary) outcome indicators. These variations have been collated and are presented in the full Task Force report, which also includes a practical ''handbook'' of methods for SIC with the wide variety of occupational agents [6].…”